The present invention relates to a two dimension unbalance correction device, and more particularly to an improved device for correcting an unbalance rotor by resolving the unbalance vector of the rotor into two components and then performing the correction procedure.
In a conventional system as shown in FIG. 1, a rotor 11 is generally supported by a pair of pedestals 14 of a balancing machine 10. The rotor 11 may be rotated by a driving device such as a driving motor (not shown). During rotation of the rotor, in case that the rotor has an initial unbalance, i.e. the mass center of the rotor is inconsistent to the rotation axis of the rotor, a centrifugal force will apply to the rotor. As a result, the centrifugal force will cause vibration and wobbling in the rotor.
It is known that the conventional balancing machine is provided with a phase detector and a pair of amplitude detectors 12 as shown in FIG. 1. The functions of the phase detector and the amplitude detectors 12 are to detect the vibration signals of the unbalance rotor 11 and transfer the signals into an unbalance vector. In addition, the balancing machine 10 is provided with a pair of vectormeters in order to indicate the unbalance vector on the vectormeter screen. Typically, the conventional vectormeter is capable of showing the magnitude and the direction of the unbalance vector by means of an indicating spotlight appearing on the screen of the vectormeter.
A flow chart shown in FIG. 2 is a general procedure of a single plane unbalance correction of a disc-shape rotor. To the right of the flow chart, there are correspondingly illustrated that different vectorial positions of the indicating spotlight appearing on the vectormeters during the correction operation. Such a general correction approach typically includes a mechanical origin adjustment step 101, an electrical compensation adjustment step 102, a trial weight adding step 103, a trial weight removing step 104, an unbalance vector measuring step 105, and an unbalance correction step 106 by adding or removing some weights on the rotor. Once the rotor reaches a unbalance condition, the indicating spotlight will appear around the center of the vectormeter. As stated above, the steps 101 and 102 imply the initial processes of the balancing machine. Steps 103 and 104 represent the scale unit normalizing procedure. Steps 105 and 106 denote the unbalancing correction procedure.
The scale unit of the vectormeter should be normalized before the performance of the unbalanced correction so that the magnitude and phase angle of the unbalance vector can be measured exactly. In the prior art, a chemical clay with a known weight is prepared and adhered to the rotor at a given position, and then the indicating spotlight of the vectormeter is adjusted to a given position to accomplish the scale unit normalizing process. After the scale unit normalizing process is done, the chemical clay must be removed from the rotor.
Conventionally, the unbalance correction method is generally performed by adding some weights opposite the unbalance vector at a certain position of the rotor. The material of additive weight is made of chemical clay. However, it is found that such conventional correction processes have the disadvantages of:
1. The scale unit of the vectormeter must be normalized by using the chemical clay. Prior to the scale unit normalizing process, the chemical clay must be prepared and weighed precisely and then adhered to the rotor at the proper position. After the scale unit normalizing process, the chemical clay must be removed from the rotor before proceeding to the next unbalance correction process. It is obvious that the performance of adhesion, weight, removal of the chemical clay is very inconvenient and wastes much time. In addition, the chemical clay is liable to adhere to the operator's hands, the rotor, and the other devices, so that it will give the user some extent of trouble. PA1 2. To correct the unbalance rotor, a flange 15 must be previously attached or fixed on the rotor 11 for the purpose of providing a containing position for retaining the chemical clay M as shown FIG. 3, in which the radius of the flange 15 is indicated by R. In order to keep the adhered chemical clay M in the containing position of the flange 15, the structure of the flange 15 must be carefully designed to have proper radius and height. Consequently, flanges with different dimenisions must be designed to match the various rotors which will increase the cost of manufacturing. PA1 3. During the unbalancing correction of the conventional method, a chemical clay with given weight is adhered to the rotor to make the rotor reach a balance condition. However, the existence of correction variables such as the weight of the chemical clay M, the radius R and the angle .theta. of the chemical clay location as shown in FIG. 4, cause the rotor to not easily reach a balance condition. Therefore, it is necessary to reperform the correction test until the rotor reaches an acceptable balance condition, which is more time consuming. PA1 1. The correction method of the present invention is simple, convenient, inexpensive, and time-saving. PA1 2. The micro-position adjustment and various choices of correction bolts are available for precisely performing the correction procedure. PA1 3. The present invention may be applied to various applications such as the polygon motor, disc drive, gyroscope, crank of an engine, fly wheel, rotor of a machine tool, propeller of marine diesel engines, etc. PA1 4. The present invention is provided with a regular correction disc which may be fixed onto the different categories of the rotor and engraved with normalized scale units and phase angle to facilitate the correction procedures.